What was the OS?

If Windows 10, simply download Media Creation Tool on another PC and use it to create bootable USB flash drive for installing Windows 10.

If Windows 7, use the Service Tag # to see if a Windows 7 image is available. https://www.dell.com/support/home/us/en/19/drivers/osiso/win

7060 is WINDOWS 10 only 64 bit only. Last model that supported 7 was the 7040.

https://www.dell.com/support/article/en-us/how13446/optiplex-7040-windows-7-driver-pack?lang=en

Systems past 2016 skylake do not support Legacy or Windows 7 or 8 and they are 64 bit only.

https://www.dell.com/support/article/en-us/sln312187/optiplex-7060-windows-10-driver-pack?lang=en

7060 what case? MT, SFF, Micro

So is the RTC coin cell battery still good. , sure it is 2018  PC.

next is hDD good ,no it is gone SSD in place.

do the MS stick builder, USB, 

power on hit F2, set safeboot off. this allows the usb installer to work

the power on again hit F12 and boot the stick

and... you know what to do once, install.exe runs first time.